Discrete MathematicsVolume 211, Issues 1–3, 28 January 2000, Pages 209-215NoteNordhaus–Gaddum results for CO-irredundance in graphsAuthor links open overlay panelE.J. Cockayne a, D. McCrea a, C.M. Mynhardt bShow moreShareCitehttps://doi.org/10.1016/S0012-365X(99)00282-4Get rights and contentUnder an Elsevier user licenseopen archiveAbstractWe prove that the sum and product of upper CO-irredundance numbers of an n-vertex graph and its complement are bounded above by n+2,(n+2)2/4, respectively, and exhibit extremal graphs for these inequalities.Previous article in issueNext article in issueRecommended articlesCited by (0)Copyright © 2000 Elsevier Science B.V. All rights reserved.